<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <script>
    function money() {
      let total = +prompt("输入银行卡余额")
      let shisu = +prompt('输入当月食宿消费金额')
      let shenghuo = +prompt('输入当月生活消费金额')
      let sum = total - shisu - shenghuo
      return sum
    }
    let re = money()
    alert(`显示银行卡剩余金额:${re}`)

  </script>
</body>
</html>